1. Field of the Invention
Aspects of the present invention relate to an image forming apparatus, and more particularly, to an image forming apparatus in which a developing part is conveniently installed to and removed from a main body.
2. Description of the Related Art
Generally, an image forming method of an image forming apparatus includes an electrophotographic method. In the electrophotographic method, an image is developed by applying developer to an electrostatic latent image formed on a photosensitive element by a potential difference and transferred to a printing paper to be formed. Another image forming method is an inkjet method, where an image is formed by discharging ink onto a printing paper through a multiplicity of inkjet nozzles. An additional image forming method is a dye-sublimation method, where an image is formed by selectively heating an ink ribbon contacted to a printing paper.
Among the methods, the electrophotographic method is widely used in an image forming apparatus because of high printing speed, high resolution and low cost. The electrophotographic type of the image forming apparatus comprises a paper feeding part, an LSU (laser scanning unit), a developing part, a fixing part and a discharging part. When the paper feeding part supplies a printing paper to the developing part and the LSU scans the laser, the developing part selectively applies developer onto the printing paper to form a printed image. The fixing part fixes the applied developer onto the printing paper by applying heat and pressure. The discharging part receives the printing paper with the fixed developer from the developing part and discharges the printing paper to the outside.
The developing part comprises a photosensitive element, a developing roller and a fixing roller. When the LSU scans the laser onto the photosensitive element to form an electrostatic latent image, the developing roller develops an image by supplying the developer to the latent image. The fixing roller transfers the developed image formed on the photosensitive element to the printing paper. Generally, the developing part is provided as a supply which can be installed in and removed from a main body of the image forming apparatus according to such factors as when the developer supply is exhausted, the durability of the developing part, malfunctions, etc.
FIG. 1 is an exploded side view of a conventional image forming apparatus 100. As shown in FIG. 1, the image forming apparatus 100 comprises a developing part 110 and a main body 120. The developing part 110 comprises a plurality of developing process rollers 112, a photosensitive element (not shown) and other items to perform the developing process. The main body 120 comprises an installation part 122 with respect to which the developing part 110 is installed and removed. The developing part 110 is installed in and removed from the installation part 122 in an installing and removing direction A. The installing and removing direction A is perpendicular to an extending direction of the developing process roller 112. The developing part 110 comprises a handling part 170 at one end thereof to be handled by a user.
The installation part 122 comprises a roller driving part 124 disposed to engage with the developing process roller 112 when the developing part 110 is installed at the installation part 122. The roller driving part 124 transfers a driving force to the developing process roller 112, so that the developing part 110 can perform a predetermined developing process.
The installation part 122 comprises a position restricting groove part 126 and the developing part 110 comprises a position restricting protrusion 114. The position restricting groove part 126 extends to have a predetermined length in a predetermined position restricting direction B, which is approximately perpendicular to the installing and removing direction A of the developing part 110. When the developing part 110 is installed at the installation part 122, the position restricting protrusion 114 is held in the position restricting groove part 126, so that the developing process roller 112 can engage with the roller driving part 124.
A pressing member 150 presses the developing part 110 to fix the installing position of the developing part 110 when the developing part 110 is installed at the installation part 122. Accordingly, the developing process roller 112 is prevented from being detached from the roller driving part 124 while the developing part 110 is performing the developing process. An elastic member 152 elastically supports the pressing member 150 to increase the pressure of the pressing member 150 against the developing part 110.
However, according to the conventional image forming apparatus 100 described above, there may be a problem that the developing part 110 is not easily removed from the installation part 122. Since the position restricting direction B is approximately perpendicular to the installing and removing direction A, if the developing part 110 is pressed simply in the installing and removing direction A, the developing part 110 may not be removed because of the engagement of the position restricting groove part 126 with the position restricting protrusion 114. For this reason, the user usually rotates the developing part 110 in a circumferential direction C or D of the developing process roller 112 while the user is holding the handling part 170 and applying force to the developing part 110 in the installing and removing direction A. In this case, the engagement of the position restricting groove part 126 with the position restricting protrusion 114 functions as a rotating pivot of the developing part 110. That is, if the user rotates the developing part 110 in the circumferential direction C or D, the developing part 110 rotates around the position restricting groove part 126 and the position restricting protrusion 114. Even if the user rotates the developing part 110, the position restricting protrusion 114 keeps the engagement with the position restricting groove part 126 only with a different contact angle.
Specifically, the pressing member 150 is disposed to approximately correspond to a position where the position restricting protrusion 114 engages with the position restricting groove part 126, so that the pressing member 150 presses the developing part 110 in a direction E. Accordingly, the pressure of the pressing member 150 prevents the position restricting protrusion 114 from detaching from the position restricting groove part 126 and may cause more inconvenience to the user in removing the developing part 110 from the installation part 122.